Sorry for the late reply.
This should resolve the issue.
Do not include 2-byte characters (e.g. Japanese) in the installed directory or in the hierarchy up to that point. The game will not work.
The API key may be incorrect, and
The API key may have expired.
If you make your ChatGPT.txt blank, does the game work correctly?
I just played it, English, Japanese. I was able to talk to ChatGPT in both.
Just to be sure.
Try bringing the game folder directly under the C drive and starting it up.
Did it work safely?